Defense. Goalies are too hot/cold and variable from year to year. There are maybe 5-7 guys in the entire league that are consistently good from year to year. A real top-pairing dman needs to be the priority, just like it should have been last year, and the year before, and the year before, and the year before.
Everybody is going to say "but we have Bouchard, Broberg, Lagesson, Bear, Jones, and Samorukov all coming down the pipeline". Yes, and not one of them is going to be a top-pairing dman. If you can trade Broberg + something to get back a top-pairing guy, you do that in a heartbeat. Additionally, other than maybe Bear, all those players are 2-3 years away from moving the needle and not needing sheltering at even strength. Our window to win is the next 5 years until 29's contract is over, full stop. Waiting, and praying, for one of those guys to magically turn into a top-pairing guy in 3 years isn't a plan, its a prayer to the hockey gods.